RF repeater and mobile unit with cancellation of interference from a repeated signal

Abstract

A radio frequency repeater device includes a receive antenna that receives a receive signal having a first frequency. A transmit antenna transmits a repeat signal at the first frequency, the repeat signal being an amplified version of the receive signal. A signal filter communicates with the receive antenna and transmit antenna, the signal filter being operable to amplify quadrature and non-quadrature components of an input signal associated with the repeat signal to produce a filtered repeat signal. A coupler combines the receive signal with the filtered repeat signal in such a way that the filtered repeat signal cancels interference from the transmitted repeat signal in the receive signal.

That which is claimed is: 
     
       1. A cellular communications method comprising, in a cellular communications network:
 (a) receiving by a first mobile unit a wirelessly transmitted signal from a second mobile unit or a base station; 
 (b) forming a repeat signal by the first mobile unit, the repeat signal being an amplified version of the wirelessly transmitted signal in (a); 
 (c) transmitting the repeat signal from the first mobile unit; and 
 (d) cancelling interference caused by transmitting the repeat signal in (c) using a signal filter on the first mobile unit that amplifies quadrature and non-quadrature components of an input signal associated with the repeat signal to produce a filtered repeat signal. 
 
     
     
       2. The method of  claim 1 , wherein the wirelessly transmitted signal and signal transmitted in (c) have overlapping frequencies. 
     
     
       3. The method of  claim 1 , wherein the wirelessly transmitted signal is being received at the same time the signal transmitted in (c) is being transmitted. 
     
     
       4. The method of  claim 1 , wherein the first mobile unit is a cellular telephone. 
     
     
       5. The method of  claim 1 , wherein the quadrature components of the input signal are 90 degrees out of phase with each other and the non-quadrature components of the input signal are not 90 degrees out of phase with each other. 
     
     
       6. The method of  claim 1 , wherein the signal filter includes a signal weight adjuster adapted to impart separate signal weights to the quadrature and non-quadrature components of the input signal. 
     
     
       7. The method of  claim 1 , wherein the first mobile unit is configured to transmit and receive signals at the same frequency simultaneously. 
     
     
       8. An electronic device comprising:
 a mobile unit having an antenna that transmits and receives radio signals within a cellular network, the mobile unit including:
 a repeater in communication with a receive signal path and transmit signal path, the repeater being operable to pass a repeated signal associated with the receive signal to the transmit signal path; and 
 a signal filter communicating with the receive signal path and transmit signal path, the signal filter being operable to amplify quadrature and non-quadrature components of an input signal associated with the repeat signal to produce a filtered repeat signal and to cancel interference caused by the repeated signal in the receive signal path with the filtered repeat signal. 
 
 
     
     
       9. The device of  claim 8 , wherein the mobile unit transmits and receives radio signals at overlapping frequencies. 
     
     
       10. The device of  claim 8 , wherein the mobile unit transmits and receives radio signals at overlapping frequencies simultaneously. 
     
     
       11. The device of  claim 8 , wherein the quadrature components of the input signal are 90 degrees out of phase with each other and the non-quadrature components of the input signal are not 90 degrees out of phase with each other. 
     
     
       12. The device of  claim 8 , wherein the signal filter includes a signal weight adjuster adapted to impart separate signal weights to the quadrature and non-quadrature components of the input signal. 
     
     
       13. The device of  claim 8 , wherein the mobile unit is a cellular telephone. 
     
     
       14. A radio frequency repeater device comprising:
 a receive antenna that receives a receive signal having a first frequency; 
 a transmit antenna that transmits a repeat signal at the first frequency, the repeat signal being an amplified version of the receive signal; 
 a signal filter communicating with the receive antenna and transmit antenna, the signal filter being operable to amplify quadrature and non-quadrature components of an input signal associated with the repeat signal to produce a filtered repeat signal; and 
 a coupler that combines the receive signal with the filtered repeat signal in such a way that the filtered repeat signal cancels interference from the transmitted repeat signal in the receive signal. 
 
     
     
       15. The device of  claim 14 , wherein the transmit antenna and receive antenna are the same antenna. 
     
     
       16. The device of  claim 14 , wherein the quadrature components of the input signal are 90 degrees out of phase with each other and the non-quadrature components of the input signal are not 90 degrees out of phase with each other. 
     
     
       17. The device of  claim 14 , wherein the signal filter includes a signal weight adjuster adapted to impart separate signal weights to the quadrature and non-quadrature components of the input signal. 
     
     
       18. The device of  claim 14 , wherein the transmit antenna and receive antenna transmit and receive at overlapping frequencies simultaneously. 
     
     
       19. The device of  claim 14  on a cellular telephone.